The air horn blast comes from stadium horns, but its MLG form spread in the early 2010s through gaming montage parodies on YouTube, where editors layered it over Call of Duty trick shots with dubstep, Doritos and Mountain Dew jokes. MLG, or Major League Gaming, became shorthand for that exaggerated pro gamer style. The clip spread as a staple of meme montages and reaction edits, and it remains popular because one blast instantly signals ironic hype, mock skill and a knowingly ridiculous celebration.